Re: Library extension point / customization for UDTs [WAS: out_ptr's formal review starts now!]

From: JeanHeyd Meneide (phdofthehouse_at_[hidden])
Date: 2019-06-26 22:48:20

On Wed, Jun 26, 2019 at 4:01 AM Gavin Lambert via Boost <
boost_at_[hidden]> wrote:

> There have been a few standards proposals to fix this for std::hash in
> particular by doing something different.  But currently it looks like
> the standard in general is heading down the track of defining even more
> things that need to be specialised, rather than the reverse.
>
> I'm not aware of any general fix being proposed, but I also don't really
> follow these things.
>

     They are attempting to make this easier, but the proposal author
hasn't been around when it was discussed (Last discussed during the C++
Standardization Meeting in Rapperswil). The paper is p0665:
https://wg21.link/p0665

     I have concerns about all of the ways we do extension in C++ currently
(that was the point of the talk I linked in the originating thread). There
are a lot of tradeoffs. Hopefully Matt Calabrese's p1292 - Customization
Point Functions <https://wg21.link/p1292> will make a lot of that go away.

Sincerely,
JeanHeyd Meneide